**4. Investigation of the Impact of the DER and ESS on VPP Planning and Operating Conditions—A Case Study**

Discussed technical aspects related to the impact of DERs on the operating condition of the network or power control strategy applied in DERs are primarily addressed to the integration of DER with the power systems. However, the revealed aspects can be treated as boundary conditions in terms of VPP planning and operation strategies. This section aims to present methods that can be used to solve three formulated in the problem statement topics. These issues are investigated based on a real VPP project. The obtained results are associated with the investigated localization of the VPP however can be treated as an example of a method for the assessment of formulated topics. These topics are as follows:

